Introduction
In the food industry, there are several processes for applying an antimicrobial food additive to the surface of food products: spraying, incorporation into the formulation, glazing, or immersion. Among these approaches, immersion is often one of the simplest solutions to integrate into a production line while ensuring uniform coverage of the product.
The Procedure
The principle involves completely immersing the product for a few seconds in a solution containing the processing aid. This immersion ensures contact with the entire surface of the food, including areas that are more difficult to reach by spraying. This method is particularly well-suited for fresh, frozen, or ready-to-eat products such as seafood, cut fruits and vegetables, and certain dairy products like brined cheeses.
Maintaining Bath Performance with Respiking
Over the course of production, a soaking bath naturally changes. Each batch of product removes a small amount of solution, fresh water may dilute the bath, and proteins, fats, and other organic material gradually accumulate. Left unmanaged, these changes can reduce the concentration of the antimicrobial and affect the consistency of the application.
To address this, many processors implement a respike program. Rather than replacing the entire bath, a predetermined amount of antimicrobial is added at defined intervals to restore the target concentration. Once established during process validation, this approach helps maintain consistent antimicrobial performance throughout the production run while reducing unnecessary solution changes and production interruptions. For facilities running long production shifts, respiking provides a practical way to preserve process consistency and maximize the value of the soaking bath.
Key Benefits
One of the main advantages of the soaking bath is how easy it is to integrate. Many plants already have a brining, glazing, or cooling tank. Adding an antimicrobial agent at this stage often helps strengthen microbiological control without significantly altering the manufacturing process. To ensure consistent performance, however, several parameters must be controlled:
- The concentration of the solution must remain uniform through gentle agitation or recirculation of the bath;
- The immersion time must be sufficient to allow for complete wetting of the surface,
- And finally, the draining time must be adequate to minimize solution loss before the next step.
Like any process bath, the solution gradually accumulates organic matter (proteins, lipids, product juices, particles). This organic load varies depending on the type of food and the ratio of the volume of soaked product to thevolume of the soaking bath. It is therefore recommended to establish, during initial industrial validation, an appropriate replacement frequency (for the bath water or the antimicrobial solution) in order to maintain optimal application conditions.
INNEO, A Precision Approach to Listeria Control
In the case of INNEO, this application method offers several advantages. The antimicrobial agent is applied directly to the area where the risk of contamination is greatest: the product surface. The dip bath enables uniform, reproducible, and easily validated application in industrial settings while integrating seamlessly with existing processing equipment, without requiring additional labor. Additionally, no minimum contact time is required, full immersion is sufficient to activate INNEO’s antimicrobial protection. When well-designed and properly validated, a dip bath is a simple, low-cost, and highly reproducible method for adding an additional hurdle against Listeria monocytogenes to virtually any existing production line without compromising operational efficiency.
